The specific aims are 1. To determine the effects of an 18 month period of supervised, verified exercise, resulting in an approximate increase in energy expenditure of 140,800 kcal on body weight and body composition in overweight college students; 2. To determine the manner in which exercise alters energy balance through changes in energy intake and total energy expenditure, leading to the observed changes in body weight and composition and to determine if an 18 month period of exercise reduces risk factors for cardiovascular disease and diabetes.